The crane index can be a measure of a city on the move, but far north Queensland ecologists believe the developing skyline of Cairns has devastated the city's most valuable natural asset — its wildlife.

Hundreds of baby bats are dying or being abandoned as cranes work on high-rise developments in the centre of Cairns.

Ecologist Martin Cohen believes the development and deaths are connected.

"It's not unusual to get orphaned bats around this camp, however this year we're getting extraordinary numbers," he said.

"It's a perfect storm for this camp. There's just too much going on around it, which stresses the animal so much that they give birth too young or they abandon their young."

Six cranes have been erected this year to work on several new projects, including a $370 million multi-tower high-rise development.

Is price of development too high?

Dr Cohen did not believe the developers were in breach of environmental guidelines.

But he questioned the scale and speed of development in the Cairns CBD and said the city needed to better plan around its wildlife.

"In my opinion it's a bit of overkill [in terms of] the extent of the development, considering there's a nationally significant and threatened flying fox camp over the road," he said.

"People come here to see the natural world and our wildlife, and at the moment it's death by a thousand cuts … we're turning the Cairns CBD into a concrete jungle."

The council argues the development strikes a balance between progress and wildlife protection.

City wins awards for urban planning

A Cairns Regional Council spokesperson said all new developments were required to comply with the principles of tropical urbanism, which included an emphasis on maintaining or creating tropical-style vegetation corridors.

The city has won national urban planning awards for its tropical urbanism concept, while Cairns has also been recognised as having one of the highest rates of tree canopy cover in Australia.

Prime Group, which is building the project, also disputed the development was impacting the colony, and said it was working closely with the council, the Department of Environment Heritage and Protection, and its own ecologists.

In a statement, the company said:

R2G Environmental Consultants have been commissioned by Prime Constructions to monitor spectacled flying foxes (SFF) at the Cairns CBD roost during construction to fulfil the conditions of the State and Commonwealth approvals for the project.

The objective of monitoring activities is to identify significant events that result in disturbance of the SFF at the adjacent roost that may impact the health of the colony.

R2G undertake weekly counts of SFF. To date disturbances, identified as greater than 30 per cent, have not occurred.

A spokesperson for Department of Environment, Heritage and Protection confirmed it had found no causal link.